Electrode design for electrohydrodynamic conduction pumping

ABSTRACT

An electrohydrodynamic conduction liquid pumping system includes a vessel configured to contain a liquid or a liquid/vapor therein. This vessel can be of a elongate conduit configuration, an elongate channel configuration or a liquid enclosure configuration. At least a single pair of electrodes are disposed in a spaced apart relation to each other on the vessel and configured to be oriented in the liquid. A power supply is coupled to the electrodes and operable to generate electric fields in between the pair of electrodes, the electric forces inducing a net liquid movement relative to the vessel. Various electrode designs are embraced within the concept of this invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 USC 371 ofPCT/US03/18930, filed Jun. 16, 2003 which claims the benefit of U.S.Provisional Application Ser. No. 60/390,848, filed Jun. 21, 2002.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The U.S. government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms as provided for by the terms of Contract No.32525-54750 awarded by NASA—Headquarters—Microgravity Fluid PhysicsProgram.

BACKGROUND OF THE INVENTION

The subject matter of this disclosure is related to the disclosure inco-pending application Ser. No. PCT/US01/22803, filed Jul. 18, 2001, nowU.S. Pat. No. 6,932,580, which is incorporated herein by reference. Withthe discovery set forth therein, there became an ever increasing demandfor improved conduction pumping characteristics. Various new electrodeconfigurations were investigated by me and found to be successful andare the subject matter of this disclosure.

SUMMARY OF THE INVENTION

An electrohydrodynamic conduction liquid pumping system includes avessel configured to contain a liquid or a liquid/vapor therein. Thisvessel can be of a elongate conduit configuration, an elongate channelconfiguration or a liquid enclosure configuration. At least a singlepair of electrodes are disposed in a spaced apart relation to each otheron the vessel and configured to be oriented in the liquid. A powersupply is coupled to the electrodes and operable to generate electricfields in between the pair of electrodes, the electric forces inducing anet liquid movement relative to the vessel. Various electrode designsare embraced within the concept of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and purposes of this invention will be apparent to personsacquainted with apparatus of this general type upon reading thefollowing specification and inspecting the accompanying drawings, inwhich:

FIG. 1 is a schematic illustration of a first embodiment of a conductionpumping mechanism consisting of a high voltage ring electrode and a ringelectrode ground oriented on a conduit configured to convey a liquidtherein;

FIG. 2 is a schematic illustration of a second embodiment of aconduction pumping mechanism;

FIG. 3 is a schematic illustration of a third embodiment of a conductionpumping mechanism which includes two radially spaced rings configuredfor high voltage in conjunction with a grounded ring electrode;

FIG. 4 is a schematic illustration of a fourth embodiment of aconduction pumping mechanism having three radially spaced ringelectrodes configured for high voltage application in conjunction with agrounded ring electrode;

FIG. 5 is a schematic illustration of a fifth embodiment of a conductionpumping mechanism utilizing spaced tubes suspended in a conduit andconfigured for high voltage application in conjunction with a groundedring electrode;

FIG. 6 is a schematic illustration of a sixth embodiment of a conductionpumping mechanism having a plate with multiple holes providedtherethrough and configured for high voltage application in conjunctionwith a grounded ring electrode;

FIG. 7 is a longitudinal cross sectional view of a conduction pumpingmechanism corresponding in concept to FIG. 6;

FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. 7;

FIG. 9 is a longitudinal sectional view corresponding to FIG. 6;

FIG. 10 is a sectional view taken along the line X-X of FIG. 9;

FIG. 11 is a schematic illustration of a seventh embodiment of aconduction pumping mechanism wherein concentric annular rings areconfigured for high voltage are suspended within the conduit and inconjunction with a grounded ring electrode;

FIG. 12 is a schematic illustration of an eighth embodiment of aconduction pumping mechanism similar to FIG. 1 wherein the high voltageelectrode is of a differing configuration;

FIG. 13 is a schematic illustration of a ninth embodiment of aconduction pumping mechanism similar in concept to FIGS. 6-10 whereinthe high voltage electrode is a porous plate or disc through which allof the liquid must pass;

FIG. 14 is a schematic illustration of a tenth embodiment of aconduction pumping mechanism wherein the plate or disc is porous and issmaller in cross section than the cross section of the conduit;

FIG. 15 is a schematic illustration of an eleventh embodiment of aconduction pumping mechanism similar to FIG. 13 wherein an annular ringis porous;

FIGS. 16-19 are respective cross sectional views illustrating differingporosities of the high voltage electrode corresponding to FIG. 13;

FIG. 20 is a schematic illustration of a conduction pumping thermalenergy transfer system wherein liquid is present on the outer surface ofa heat transfer element;

FIG. 21 is a plan view of a high voltage electrode utilized in FIG. 20;

FIG. 22 is a schematic illustration of a conduction pumping thermalenergy transfer system wherein liquid is present on the inside surfaceof the conduit and the electrode of FIG. 21 is oriented inside theconduit;

FIGS. 23 to 25 are enlarged schematic illustrations of alternateelectrode configurations for the embodiments of FIGS. 20 and 22;

FIG. 26 is a schematic illustration of a conduction pumping thermalenergy transfer system in a channel environment;

FIG. 27 is a schematic illustration similar to FIG. 23 except that thehigh voltage electrode is in the form of parallel plates;

FIG. 28 is a schematic illustration similar to FIG. 23 except that thehigh voltage electrode is of a differing configuration;

FIG. 29 is a schematic illustration of a vessel housing liquid thereinand in which is provided a conduction pumping mechanism;

FIG. 30 is a schematic illustration of a vessel partially filled withliquid and in which is provided a conduction pumping mechanism; and

FIG. 31 is a schematic illustration of a manifold having a single liquidinput and plural liquid outputs with one or more conduction pumpingmechanisms oriented in each of the outlets in order to balance theliquid flow through each of the outlets.

DETAILED DESCRIPTION

The concept of conduction pumping is set forth in detail in pendingapplication Serial No. PCT/US01/22803, filed Jul. 18, 2001. Thus,further discussion concerning the concept is believed unnecessary,especially since the disclosure in that application is incorporatedherein by reference.

Referring to FIG. 1, there is provided an elongate conduit C configuredfor transporting a liquid therethrough. A ground electrode 10 isprovided on the conduit with the radially inner surface of the electrode10 being flush with the inside surface 11 of the conduit C. A ring highvoltage electrode 12 is mounted to the inside surface 11 of the conduitC with the cross section of the ring extending from the inside wall ofthe conduit radially inwardly a finite distance. FIG. 2 illustrates aconduction pumping mechanism similar to FIG. 1 except that the highvoltage electrode 13 is configured so that the inside surface 14 thereofis flush with the inside surface 11 of the conduit C. It is to beunderstood that the term “flush” as used herein and elsewhere is toembrace locations wherein the electrodes are spaced radially inwardlyand outwardly from the surface 11 a small distance.

FIG. 3 illustrates a conduction pumping mechanism similar to FIG. 1except that an additional ring 16 is concentrically oriented inside thering 12 with both rings being connected to a high voltage source V. FIG.4 is similar to FIG. 3 except that there is an additional ring 17concentrically disposed relative to the two other rings 12 and 16. Inthe embodiment of FIGS. 3 and 4, the centrally disposed rings 16 and 17are suspended by the electrical connection 18 that serves to connecteach of the rings to the high voltage source V.

FIG. 5 is a schematic illustration of a conduction pumping mechanisminside a conduit C and with a ground ring electrode 10 identical to thatin the preceding FIGS. 1-4. A plurality of hollow tubes 19 are suspendedinside the conduit C by connection to the electrical conductor 18 thatconnects the aforesaid hollow tubes 19 to a high voltage source V. Inthis particular embodiment, the central axes of the hollow tubes 19 areparallel to each other and parallel to the longitudinal axis of theelongate conduit 19. In this particular embodiment, and as depicted bythe arrows of the total net flow of liquid occurring across the crosssection of the conduit, only some of the liquid will pass through theinterior of the hollow tubes 19.

FIG. 6 schematically illustrates a conduction pumping mechanismutilizing a grounded electrode 10 identical to the grounded electrodesdiscussed above with respect to FIGS. 1-5. A flat plate or disc 21having a plurality of holes 22 extending therethrough and on axes thatare parallel to each other and to the longitudinal axis of the elongateconduit C is provided. The flat plate 21 is mounted to the insidesurface 11 of the conduit C. The flat plate 21 is connected by anelectrical connection 18 to a high voltage source V.

FIGS. 7 and 8 illustrate a configuration wherein the diameter of theholes 22 in the flat plate 21 have a diameter of 1.14 mm. FIGS. 7 and 8furthermore illustrate the structure of the conduit for facilitating anorienting of multiple pairs of electrodes along the length of theconduit C. FIGS. 9 and 10, on the other hand, are similar to FIGS. 7 and8 and illustrate that the diameter of the holes 22 in the flat plate 21are 1.59 mm. FIGS. 7-10 also illustrate that the flat plate 21 can beoriented inside the conduit C by suspending it from the electricalconductor 18 facilitating connection thereof to the high voltage sourceV.

FIG. 11 schematically illustrates a conduction pumping mechanism similarto FIG. 3 except that the two annular rings which are concentric witheach other and with the longitudinal axis of the conduit C and aresuspended in the interior of the conduit by the electrical connection 18which facilitates connection of the rings 23 and 24 to the high voltagesource V. While two rings 23 and 24 are illustrated, more rings can beprovided where desirable. In this particular embodiment, and as depictedby the arrows, of the total net flow of liquid occurring across thecross section of the conduit, only some of the liquid will pass throughthe interior of the rings 23 and 24. The grounded ring electrode 10 isidentical to the configurations shown in the preceding figures.

FIG. 12 is similar to FIG. 1 except that the electrode 26, correspondingto the electrode 12 in FIG. 1, is of a rounded configuration to form arounded protuberance extending radially inwardly from the interior wall11 of the conduit C. The grounded ring electrode 10 is identical to theconfiguration illustrated in FIG. 1. The electrical connection 18facilitates connection of the electrode 26 to a high voltage source V.

FIG. 13 illustrates a flat plate or disc 27 which is porous and which isconnected by the electrical connection 18 to the high voltage source V.The grounded ring electrode 10 is identical to the grounded ringelectrodes discussed above.

FIG. 14 schematically illustrates a conductive pumping mechanism whereina flat plate or disc 28 is porous and is suspended in the conduit C bythe electrical connection 18 in generally the central region of thecross section of the conduit. The grounded ring electrode 10 isidentical to the electrodes shown and described above. The annularporous flat plate or disc 28A as shown in FIG. 15 is supported by theconduit C.

FIGS. 16-19 disclose embodiments corresponding to FIG. 13. FIGS. 16 and17 illustrate a porous plate or disc wherein the porosity is 0.2 micronsin FIGS. 16 and 17 and 40.0 microns in FIGS. 18 and 19. In addition,FIGS. 16-19 illustrate the format for the conduit and the electrodes 27and 10 so that a multiple set of pairs can be oriented one after theother along the length of the conduit C to facilitate conduction pumpingof the liquid being transported through the conduit C and through theporous electrode 27.

FIG. 20 illustrates an electrohydrodynamic conduction pumping thermalenergy transfer system which utilizes a conduit having inside surface 41and exterior surface 42. A grounded ring electrode 43 is provided on theexterior surface of the conduit and is axially spaced from an annularhigh voltage ring electrode plate 44 having a finite radial width asillustrated in FIG. 21. The ring electrode 44 has a plurality ofside-by-side holes 46 extending therethrough. In this particularembodiment, the holes are cylindrical in nature although they could beof other configurations as well. The high voltage electrode 44 isconnected through an electrical connection 47 to a high voltage sourceV. The high voltage electrode 44 is oriented axially spaced from thegrounded ring electrode 43 in a manner similar to the configurationsdiscussed above. In this particular embodiment, a cooling medium istransported through the interior of the conduit C so that, in a twophase liquid environment, a liquid condensate will form on the exteriorsurface of the conduit C. The electrodes 43 and 44 are configured to beoriented in the liquid condensate and when electrical energy is appliedto the electrodes, the liquid condensate and a limited amount of theadjacent vapor phase will be conductively pumped longitudinally of theconduit simultaneously while new condensation is forming on the exteriorsurface of the conduit C.

FIG. 20 could also be utilized in an environment where a heating mediumis pumped through the interior of the conduit C to effect an evaporationof liquid interfacing with the exterior surface of the conduit C. Inthis instance, electrical energy applied to the electrodes 43 and 44would effect movement of the liquid to facilitate a more efficientevaporative process.

FIG. 22 is similar to FIG. 20 except that liquid is present on theinside surface 41 of the conduit 42. The ring electrode 43A and the ringelectrode 44A are provided on the inside surface of the conduit C andare configured to be oriented within the liquid layer. The plural holesthrough the electrode 46 are also within the liquid, as is the case inthe preceding embodiment so that liquid will pass through the holes 46as a result of the conduction pumping phenomena. FIG. 22 is configuredto be utilized in an environment where the liquid is a condensate or isa liquid to be evaporated in a manner similar to that described abovefor FIG. 20.

It is to be understood that in regions of the conduit whereat heattransfer is not taking place, arranging series arrays of electrode pairsin any liquid present thereat will, when appropriately energized,facilitate the movement thereof to a desired destination.

FIGS. 23 to 25 illustrate different electrode designs for theembodiments of FIGS. 20 and 22. FIG. 23 schematically illustrates anelectrode design 43B, 44B similar to FIG. 1. FIG. 24 schematicallyillustrates a grounded electrode 43B similar to FIG. 23 while the highvoltage electrode 44C is in the form of rings concentric with the axisof the conduit C. FIG. 25 schematically illustrates an electrode design44D, 44B similar to FIG. 12.

While in the preceding discussion the conduits and electrodes have beendepicted as circular in cross section, it is to be understood that allnon-circular cross sections are embraced within the scope of thisdisclosure. That is, the conduits and electrodes can have an ellipticalcross section and the like or a polygonal cross section.

FIG. 26 schematically illustrates a conduction pumping mechanism 50 usedin association with a liquid guiding channel 51. In this embodiment, thegrounded electrode 52 is a plate oriented flush with the bottom surface53 of the channel 51. The high voltage electrode 54 is connected by anelectrical connection 56 to a high voltage source V. In this particularembodiment, the high voltage electrode protrudes into the interior ofthe channel and both electrodes 52 and 54 are configured to be orientedwithin the liquid.

FIG. 27 is similar to FIG. 26 except that the high voltage electrode isa pair of parallel plates 57 extending parallel to the longitudinal axisof the channel 51 and to the bottom surface 53 of the channel 51.

FIG. 28 is similar to FIG. 26 except that the high voltage electrode 58has a rounded surface configuration as compared to the more rectangularversion illustrated in FIG. 26.

FIG. 29 schematically illustrates a vessel 60 housing a liquid thereinwith a grounded ring electrode 61 oriented so that the interior surfacethereof is flush with the interior surface 62 of the vessel 60. Anelongate bar 63 is oriented inside the vessel 60 and is configured toserve as the high voltage electrode connected through an electricalconnection 64 to the high voltage source V. In this particularembodiment, and since the vessel is closed, electrical energy applied tothe electrodes 61 and 63 will effect a circulatory motion of the liquidin directions indicated by the arrows 66-69. This configuration willfacilitate in circulatory motion of liquids in environments wherecirculation is required.

FIG. 30 schematically illustrates a vessel 60A partially filled withliquid 65. Electrical energy applied to the electrodes 61A and 63A willeffect a circulatory motion of the liquid in directions indicated by thearrows 66-67.

FIG. 31 schematically illustrates a manifold 70 having a liquid inletport 71 and plural liquid outlet ports 72. The liquid outlet ports 72are in the form of conduits similar to the conduits described above andeach conduit has a series of electrodes therein. The volume of liquidpassing through each conduit 72 is monitored by a detector 73 and thevoltage of the power supply is determined by a signal transmitted fromthe liquid flow detector 73 through the control lines 74 to the powersupply to regulate the amount of high voltage V applied to the highvoltage electrodes. The conduction pumping mechanisms in each conduitwill therefore serve to effect an equalized flow of single phase liquidor two phase liquid/vapor through each of the conduits. It isadditionally possible for the liquid flow detection device 73 toseparately monitor the liquid flow through each conduit so that acorresponding electrical signal will be sent through a correspondingcontrol line 74 to multiple and separate power supplies so that thevolume of liquid being conduction pumped through each conduit will beprecisely regulated.

Embraced within this disclosure is the feature of vapor depositing theelectrodes onto the surface of the conduit or channel. Also embracedwithin this disclosure is the use of the conduction pumping mechanism tofacilitate pumping of liquid and any bubbles therein.

While the electrodes have been illustrated in the drawings as havingsharp corners, edges and the like, it is to be understood that thecorners and edges of all electrodes are radiused. The magnitude of theradius is a function of the magnitude of the voltage and the magnitudeof the electric fields. The rounded corners and edges will prevent ioninjection during conduction pumping.

A grounded electrode has been specifically referenced in each of theabove embodiments. It is to be understood that the phrases “high voltageelectrode” and “high voltage source” as used herein and throughoutmerely indicate that there is to exist a sufficient potential differencebetween the electrodes to generate electric fields therebetween.

Although particular preferred embodiments of the invention have beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, includingthe rearrangement of parts, lie within the scope of the presentinvention.

1. An electrohydrodynamic conduction liquid pumping system, comprising:an elongate conduit configured to transport a liquid; at least a singlepair of electrodes disposed in a spaced apart relation to each otherinside the conduit and configured to be oriented in the liquid; a powersupply coupled to the electrodes and operable to generate electricfields in between said pair of electrodes, the electric forces inducinga net axial movement of the liquid along the conduit; and a firstelectrode of said pair of electrodes comprising a first electricallyconductive element oriented so that it is flush with an inside surfaceof said conduit and is electrically coupled to a first potential sourceof said power supply, a second electrode of said pair of electrodescomprising a second electrically conductive element electrically coupledto a second potential source on said power supply and being configuredas a plurality of hollow tubes suspended in a plane oriented transverseto a longitudinal axis of the conduit and through which at least some ofthe liquid must pass during its net axial movement along the conduit. 2.The pumping system according to claim 1, wherein said hollow tubes eachhave an axis extending parallel to the longitudinal axis of saidconduit.
 3. The pumping system according to claim 2, wherein said hollowtubes are in the form of an integral porous plate contained in a planeoriented transverse to a longitudinal axis of the conduit and throughwhich all of the liquid must pass during its net axial movement alongthe conduit.
 4. The pumping system according to claim 3, wherein saidporous plate is a plate having a plurality of axially extendingside-by-side cylindrical holes therethrough.
 5. The pumping systemaccording to claim 4, wherein a diameter of each of said holes is thesame.
 6. The pumping system according to claim 4, wherein a diameter ofeach of said holes is the same and is in the range of 1.10 mm to 1.70mm.
 7. The pumping system according to claim 6, wherein the diameter is1.14 mm.
 8. The pumping system according to claim 6, wherein thediameter is 1.59 mm.
 9. The pumping system according to claim 1, whereinsaid plurality of hollow tubes are concentrically oriented and have anaxis extending parallel to the longitudinal axis of said conduit. 10.The pumping system according to claim 9, wherein two hollow tubes areconcentrically oriented.
 11. The pumping system according to claim 9,wherein three hollow tubes are concentrically oriented.
 12. The pumpingsystem according to claim 9, wherein an outermost one of said hollowtubes is mounted to an inside surface of said conduit.
 13. The pumpingsystem according to claim 12, wherein two hollow tubes areconcentrically oriented.
 14. The pumping system according to claim 13,wherein three hollow tubes are concentrically oriented.
 15. The pumpingsystem according to claim 1, wherein said first potential source is aground potential.
 16. An electrohydrodynamic conduction liquid pumpingsystem, comprising: an elongate conduit configured to transport aliquid; at least a single pair of electrodes disposed in a spaced apartrelation to each other inside the conduit and configured to be orientedin the liquid; and a power supply coupled to the electrodes and operableto generate electric fields in between said pair of electrodes, theelectric forces inducing a net axial movement of the liquid along theconduit; and a first electrode of said pair of electrodes comprising afirst electrically conductive element oriented so that it is flush withan inside surface of said conduit and is electrically coupled to a firstpotential source of said power supply, a second electrode of said pairof electrodes comprising a second electrically conductive elementelectrically coupled to a second potential source of said power supplyand being configured as a flat plate, at least a portion of said flatplate being porous.
 17. The pumping system according to claim 16,wherein said porous portion has a porosity in the range of 0.2 micronsto 50 microns.
 18. The pumping system according to claim 17, wherein theporosity of said plate is 0.2 microns.
 19. The pumping system accordingto claim 17, wherein the porosity of said plate is 40 microns.
 20. Thepumping system according to claim 16, wherein all of said flat plate isporous.
 21. The pumping system according to claim 16, wherein an annulussegment of said flat plate is porous.
 22. The pumping system accordingto claim 16, wherein a central section of said flat plate is porous. 23.An electrohydrodynamic conduction liquid pumping system, comprising: anelongate conduit configured to transport a liquid; at least a singlepair of electrodes disposed in a spaced apart relation to each otherinside the conduit and configured to be oriented in the liquid; a powersupply coupled to the electrodes and operable to generate electricfields in between said pair of electrodes, the electric forces inducinga net axial movement of the liquid along the conduit; and a firstelectrode of said pair of electrodes comprising a first electricallyconductive element oriented so that it is flush with an inside surfaceof said conduit and is electrically coupled to a first potential sourceof said power supply, a second electrode of said pair of electrodescomprising a second electrically conductive element electrically coupledto a second potential source on said power supply and being configuredas a profile mounted to an inside surface of said conduit.
 24. Thepumping system according to claim 23, wherein said conduit is a channeland wherein said channel is configured to facilitate flow of the liquidtherein.
 25. The pumping system according to claim 24, wherein saidprofile is mounted flush with only a fragment of an inside surface ofsaid conduit.
 26. The pumping system according to claim 24, wherein saidprofile is a raised profile protruding from said fragment of said insidesurface of said conduit.
 27. The pumping system according to claim 26,wherein said raised profile is a profile with a curved shaped surfaceexposed to the liquid.
 28. The pumping system according to claim 26,wherein said raised profile is a profile with a polygonally-shapedsurface exposed to the liquid.
 29. The pumping system according to claim24, wherein said profile is a hollow tube suspended in the liquid. 30.The pumping system according to claim 23, wherein said firstelectrically conductive element is a first ring and wherein said profileis a second ring mounted to an inside surface of the conduit, saidsecond ring and said first ring being oriented in parallel planesoriented transverse to a longitudinal axis of said conduit.
 31. Thepumping system according to claim 30, wherein said second ring is flushwith an inside surface of said conduit.
 32. The pumping system accordingto claim 30, wherein said second ring has a raised profile forming aprotuberance on an inside surface of said conduit.
 33. The pumpingsystem according to claim 30, wherein said raised profile is a curvedprofile.
 34. The pumping system according to claim 30, wherein saidraised profile is a polygonal profile.
 35. The pumping system accordingto claim 23, wherein said first potential source is a ground potential.36. An electrohydrodynamic conductor liquid pumping thermal energytransfer system, comprising: an elongate conduit configured to transporta heating or a cooling liquid medium and having an exterior surface; atleast a single pair of electrodes disposed in a spaced apart relation toeach other on the exterior surface of the conduit and configured to beoriented in a liquid phase on the exterior surface; a power supplycoupled to the electrodes and operable to generate electric fields inthe liquid phase in between said pairs of electrodes, the electricforces inducing a net axial movement of the liquid phase along theexterior surface; and a first electrode of said pair of electrodescomprising a first electrically conductive element oriented so that itis flush with the exterior surface and is electrically coupled to afirst potential source of said power supply, a second electrode of saidpair of electrodes comprising a second electrically conductive elementelectrically coupled to a second potential source of said power supplyand being configured as a ring having an axially directed porositythrough which the liquid phase must pass during its net axial movementalong the exterior surface.
 37. The pumping thermal energy transfersystem according to claim 36, wherein said porosity is in the form ofplural side-by-side holes extending through a body of the ring, saidliquid phase passing through the holes.
 38. The pumping thermal energytransfer system according to claim 36, wherein said first potentialsource is a ground potential.
 39. An electrohydrodynamic conductionliquid pumping thermal energy transfer system, comprising: an elongateconduit having an exterior surface configured to interface with aheating or a cooling medium, said interior surface having a liquid phaselayer thereon; at least a single pair of electrodes disposed in a spacedapart relation to each other inside the conduit and configured to beoriented in the liquid phase layer; a power supply coupled to theelectrodes and operate to generate electric fields in between said pairof electrodes, the electric forces inducing a net axial movement of theliquid phase along the interior surface; and a first electrode of saidpair of electrodes comprising a first electrically conductive ringoriented in that it is flush with the interior surface and iselectrically coupled to a first potential source of said power supply, asecond electrode of said pair of electrodes comprising a secondelectrically conductive ring coupled to a second potential source ofsaid power supply and having an axially directed porosity through whichthe liquid phase must pass during its net axial movement along theinterior surface.
 40. The pumping thermal energy transfer systemaccording to claim 39, wherein said porosity is in the form of pluralside-by-side holes extending through a body of the ring, said liquidphase passing through the holes.
 41. The pumping thermal energy transfersystem according to claim 39, wherein said first potential source is aground potential.